RFIDs are slated to replace bar codes that have been in use over the past several decades and are widely expected to become ubiquitous over the next ten years. The pace transition from bar code to RFID will be faster particularly as regards newly manufactured items, and the application RFID will extend far beyond the initial sectors of economy where it starts. They are destined be used in a greater number of applications and in greater volume in the future. In time they will become pervasive in the economy of industrialized nations, then developing nations, and then currently partly developed or under-developed nations joining the ranks of the former. Areas of application for RFIDs include the following and encompass most of the economy:
RFIDs contain information about the product to which they are attached, information which in the future will go beyond that presently contained on a bar code. This has typically included an electronic product code, but will in the future include the information that presently stands in the data base of an inventory management system of an organization where the RFID Reader transmits the electronic product code it receives from the Tag, such as manufacturing and transit history, when and where made, product epedigree for traceability of constituents, options, features, etc., price history as during promotions etc.
As they are intended to steadily replace bar code usage, the roadmap set for RFID in the industry, as by the MIT Auto ID Center, its successor organization to EPCglobal, Walmart and other large retailers, as well as the DoD is that of item-level tracking.
Operation of the RFID by means of electromagnetic coupling of energy and then reflection is commonly referred to as a backscatter system. Following the power is coupling, the RFID Microchip comes alive for a brief time during which it is thus able to transfer its information to the Reader. The process may be repeated as necessary. Some RFIDs may be designed as read-only, while others allow both reading and writing. Write-once, read-only RFIDs would have their information recorded at time of manufacture or shortly thereafter and are used in applications where the information regarding the item to be tracked is not expected to be changed. Read-and-write RFIDs can have their information read as well as altered by the Reader. A class of items in this category to serve as an example would be those under warranty, where the name of the buyer (as well as the serial number of the product) could be recorded on the RFID for easy future reference.
Active, or battery-assisted passive, RFIDs are more bulky and expensive, and are used in applications where either the increased cost warrants their use or where the RFID in its passive state is in practice inadequate, as is often the case, but cannot be used in a great number of applications where cost or sheer bulk would prohibit it, such as a great many items on the supermarket shelf.